aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/go/_std_1.22/src/syscall/syscall_unix.go
blob: 4c48f29744a70ae61a909a1acc255624a0f788d8 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build unix

package syscall

import (
	errorspkg "errors"
	"internal/bytealg"
	"internal/itoa"
	"internal/oserror"
	"internal/race"
	"runtime"
	"sync"
	"unsafe"
)

var (
	Stdin  = 0
	Stdout = 1
	Stderr = 2
)

const (
	darwin64Bit = (runtime.GOOS == "darwin" || runtime.GOOS == "ios") && sizeofPtr == 8
	netbsd32Bit = runtime.GOOS == "netbsd" && sizeofPtr == 4
)

// clen returns the index of the first NULL byte in n or len(n) if n contains no NULL byte.
func clen(n []byte) int {
	if i := bytealg.IndexByte(n, 0); i != -1 {
		return i
	}
	return len(n)
}

// Mmap manager, for use by operating system-specific implementations.

type mmapper struct {
	sync.Mutex
	active map[*byte][]byte // active mappings; key is last byte in mapping
	mmap   func(addr, length uintptr, prot, flags, fd int, offset int64) (uintptr, error)
	munmap func(addr uintptr, length uintptr) error
}

func (m *mmapper) Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) {
	if length <= 0 {
		return nil, EINVAL
	}

	// Map the requested memory.
	addr, errno := m.mmap(0, uintptr(length), prot, flags, fd, offset)
	if errno != nil {
		return nil, errno
	}

	// Use unsafe to turn addr into a []byte.
	b := unsafe.Slice((*byte)(unsafe.Pointer(addr)), length)

	// Register mapping in m and return it.
	p := &b[cap(b)-1]
	m.Lock()
	defer m.Unlock()
	m.active[p] = b
	return b, nil
}

func (m *mmapper) Munmap(data []byte) (err error) {
	if len(data) == 0 || len(data) != cap(data) {
		return EINVAL
	}

	// Find the base of the mapping.
	p := &data[cap(data)-1]
	m.Lock()
	defer m.Unlock()
	b := m.active[p]
	if b == nil || &b[0] != &data[0] {
		return EINVAL
	}

	// Unmap the memory and update m.
	if errno := m.munmap(uintptr(unsafe.Pointer(&b[0])), uintptr(len(b))); errno != nil {
		return errno
	}
	delete(m.active, p)
	return nil
}

// An Errno is an unsigned number describing an error condition.
// It implements the error interface. The zero Errno is by convention
// a non-error, so code to convert from Errno to error should use:
//
//	err = nil
//	if errno != 0 {
//		err = errno
//	}
//
// Errno values can be tested against error values using errors.Is.
// For example:
//
//	_, _, err := syscall.Syscall(...)
//	if errors.Is(err, fs.ErrNotExist) ...
type Errno uintptr

func (e Errno) Error() string {
	if 0 <= int(e) && int(e) < len(errors) {
		s := errors[e]
		if s != "" {
			return s
		}
	}
	return "errno " + itoa.Itoa(int(e))
}

func (e Errno) Is(target error) bool {
	switch target {
	case oserror.ErrPermission:
		return e == EACCES || e == EPERM
	case oserror.ErrExist:
		return e == EEXIST || e == ENOTEMPTY
	case oserror.ErrNotExist:
		return e == ENOENT
	case errorspkg.ErrUnsupported:
		return e == ENOSYS || e == ENOTSUP || e == EOPNOTSUPP
	}
	return false
}

func (e Errno) Temporary() bool {
	return e == EINTR || e == EMFILE || e == ENFILE || e.Timeout()
}

func (e Errno) Timeout() bool {
	return e == EAGAIN || e == EWOULDBLOCK || e == ETIMEDOUT
}

// Do the interface allocations only once for common
// Errno values.
var (
	errEAGAIN error = EAGAIN
	errEINVAL error = EINVAL
	errENOENT error = ENOENT
)

// errnoErr returns common boxed Errno values, to prevent
// allocations at runtime.
func errnoErr(e Errno) error {
	switch e {
	case 0:
		return nil
	case EAGAIN:
		return errEAGAIN
	case EINVAL:
		return errEINVAL
	case ENOENT:
		return errENOENT
	}
	return e
}

// A Signal is a number describing a process signal.
// It implements the os.Signal interface.
type Signal int

func (s Signal) Signal() {}

func (s Signal) String() string {
	if 0 <= s && int(s) < len(signals) {
		str := signals[s]
		if str != "" {
			return str
		}
	}
	return "signal " + itoa.Itoa(int(s))
}

func Read(fd int, p []byte) (n int, err error) {
	n, err = read(fd, p)
	if race.Enabled {
		if n > 0 {
			race.WriteRange(unsafe.Pointer(&p[0]), n)
		}
		if err == nil {
			race.Acquire(unsafe.Pointer(&ioSync))
		}
	}
	if msanenabled && n > 0 {
		msanWrite(unsafe.Pointer(&p[0]), n)
	}
	if asanenabled && n > 0 {
		asanWrite(unsafe.Pointer(&p[0]), n)
	}
	return
}

func Write(fd int, p []byte) (n int, err error) {
	if race.Enabled {
		race.ReleaseMerge(unsafe.Pointer(&ioSync))
	}
	if faketime && (fd == 1 || fd == 2) {
		n = faketimeWrite(fd, p)
		if n < 0 {
			n, err = 0, errnoErr(Errno(-n))
		}
	} else {
		n, err = write(fd, p)
	}
	if race.Enabled && n > 0 {
		race.ReadRange(unsafe.Pointer(&p[0]), n)
	}
	if msanenabled && n > 0 {
		msanRead(unsafe.Pointer(&p[0]), n)
	}
	if asanenabled && n > 0 {
		asanRead(unsafe.Pointer(&p[0]), n)
	}
	return
}

func Pread(fd int, p []byte, offset int64) (n int, err error) {
	n, err = pread(fd, p, offset)
	if race.Enabled {
		if n > 0 {
			race.WriteRange(unsafe.Pointer(&p[0]), n)
		}
		if err == nil {
			race.Acquire(unsafe.Pointer(&ioSync))
		}
	}
	if msanenabled && n > 0 {
		msanWrite(unsafe.Pointer(&p[0]), n)
	}
	if asanenabled && n > 0 {
		asanWrite(unsafe.Pointer(&p[0]), n)
	}
	return
}

func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
	if race.Enabled {
		race.ReleaseMerge(unsafe.Pointer(&ioSync))
	}
	n, err = pwrite(fd, p, offset)
	if race.Enabled && n > 0 {
		race.ReadRange(unsafe.Pointer(&p[0]), n)
	}
	if msanenabled && n > 0 {
		msanRead(unsafe.Pointer(&p[0]), n)
	}
	if asanenabled && n > 0 {
		asanRead(unsafe.Pointer(&p[0]), n)
	}
	return
}

// For testing: clients can set this flag to force
// creation of IPv6 sockets to return EAFNOSUPPORT.
var SocketDisableIPv6 bool

type Sockaddr interface {
	sockaddr() (ptr unsafe.Pointer, len _Socklen, err error) // lowercase; only we can define Sockaddrs
}

type SockaddrInet4 struct {
	Port int
	Addr [4]byte
	raw  RawSockaddrInet4
}

type SockaddrInet6 struct {
	Port   int
	ZoneId uint32
	Addr   [16]byte
	raw    RawSockaddrInet6
}

type SockaddrUnix struct {
	Name string
	raw  RawSockaddrUnix
}

func Bind(fd int, sa Sockaddr) (err error) {
	ptr, n, err := sa.sockaddr()
	if err != nil {
		return err
	}
	return bind(fd, ptr, n)
}

func Connect(fd int, sa Sockaddr) (err error) {
	ptr, n, err := sa.sockaddr()
	if err != nil {
		return err
	}
	return connect(fd, ptr, n)
}

func Getpeername(fd int) (sa Sockaddr, err error) {
	var rsa RawSockaddrAny
	var len _Socklen = SizeofSockaddrAny
	if err = getpeername(fd, &rsa, &len); err != nil {
		return
	}
	return anyToSockaddr(&rsa)
}

func GetsockoptInt(fd, level, opt int) (value int, err error) {
	var n int32
	vallen := _Socklen(4)
	err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
	return int(n), err
}

func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, err error) {
	var rsa RawSockaddrAny
	var len _Socklen = SizeofSockaddrAny
	if n, err = recvfrom(fd, p, flags, &rsa, &len); err != nil {
		return
	}
	if rsa.Addr.Family != AF_UNSPEC {
		from, err = anyToSockaddr(&rsa)
	}
	return
}

func recvfromInet4(fd int, p []byte, flags int, from *SockaddrInet4) (n int, err error) {
	var rsa RawSockaddrAny
	var socklen _Socklen = SizeofSockaddrAny
	if n, err = recvfrom(fd, p, flags, &rsa, &socklen); err != nil {
		return
	}
	pp := (*RawSockaddrInet4)(unsafe.Pointer(&rsa))
	port := (*[2]byte)(unsafe.Pointer(&pp.Port))
	from.Port = int(port[0])<<8 + int(port[1])
	from.Addr = pp.Addr
	return
}

func recvfromInet6(fd int, p []byte, flags int, from *SockaddrInet6) (n int, err error) {
	var rsa RawSockaddrAny
	var socklen _Socklen = SizeofSockaddrAny
	if n, err = recvfrom(fd, p, flags, &rsa, &socklen); err != nil {
		return
	}
	pp := (*RawSockaddrInet6)(unsafe.Pointer(&rsa))
	port := (*[2]byte)(unsafe.Pointer(&pp.Port))
	from.Port = int(port[0])<<8 + int(port[1])
	from.ZoneId = pp.Scope_id
	from.Addr = pp.Addr
	return
}

func recvmsgInet4(fd int, p, oob []byte, flags int, from *SockaddrInet4) (n, oobn int, recvflags int, err error) {
	var rsa RawSockaddrAny
	n, oobn, recvflags, err = recvmsgRaw(fd, p, oob, flags, &rsa)
	if err != nil {
		return
	}
	pp := (*RawSockaddrInet4)(unsafe.Pointer(&rsa))
	port := (*[2]byte)(unsafe.Pointer(&pp.Port))
	from.Port = int(port[0])<<8 + int(port[1])
	from.Addr = pp.Addr
	return
}

func recvmsgInet6(fd int, p, oob []byte, flags int, from *SockaddrInet6) (n, oobn int, recvflags int, err error) {
	var rsa RawSockaddrAny
	n, oobn, recvflags, err = recvmsgRaw(fd, p, oob, flags, &rsa)
	if err != nil {
		return
	}
	pp := (*RawSockaddrInet6)(unsafe.Pointer(&rsa))
	port := (*[2]byte)(unsafe.Pointer(&pp.Port))
	from.Port = int(port[0])<<8 + int(port[1])
	from.ZoneId = pp.Scope_id
	from.Addr = pp.Addr
	return
}

func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from Sockaddr, err error) {
	var rsa RawSockaddrAny
	n, oobn, recvflags, err = recvmsgRaw(fd, p, oob, flags, &rsa)
	// source address is only specified if the socket is unconnected
	if rsa.Addr.Family != AF_UNSPEC {
		from, err = anyToSockaddr(&rsa)
	}
	return
}

func Sendmsg(fd int, p, oob []byte, to Sockaddr, flags int) (err error) {
	_, err = SendmsgN(fd, p, oob, to, flags)
	return
}

func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error) {
	var ptr unsafe.Pointer
	var salen _Socklen
	if to != nil {
		ptr, salen, err = to.sockaddr()
		if err != nil {
			return 0, err
		}
	}
	return sendmsgN(fd, p, oob, ptr, salen, flags)
}

func sendmsgNInet4(fd int, p, oob []byte, to *SockaddrInet4, flags int) (n int, err error) {
	ptr, salen, err := to.sockaddr()
	if err != nil {
		return 0, err
	}
	return sendmsgN(fd, p, oob, ptr, salen, flags)
}

func sendmsgNInet6(fd int, p, oob []byte, to *SockaddrInet6, flags int) (n int, err error) {
	ptr, salen, err := to.sockaddr()
	if err != nil {
		return 0, err
	}
	return sendmsgN(fd, p, oob, ptr, salen, flags)
}

func sendtoInet4(fd int, p []byte, flags int, to *SockaddrInet4) (err error) {
	ptr, n, err := to.sockaddr()
	if err != nil {
		return err
	}
	return sendto(fd, p, flags, ptr, n)
}

func sendtoInet6(fd int, p []byte, flags int, to *SockaddrInet6) (err error) {
	ptr, n, err := to.sockaddr()
	if err != nil {
		return err
	}
	return sendto(fd, p, flags, ptr, n)
}

func Sendto(fd int, p []byte, flags int, to Sockaddr) (err error) {
	var (
		ptr   unsafe.Pointer
		salen _Socklen
	)
	if to != nil {
		ptr, salen, err = to.sockaddr()
		if err != nil {
			return err
		}
	}
	return sendto(fd, p, flags, ptr, salen)
}

func SetsockoptByte(fd, level, opt int, value byte) (err error) {
	return setsockopt(fd, level, opt, unsafe.Pointer(&value), 1)
}

func SetsockoptInt(fd, level, opt int, value int) (err error) {
	var n = int32(value)
	return setsockopt(fd, level, opt, unsafe.Pointer(&n), 4)
}

func SetsockoptInet4Addr(fd, level, opt int, value [4]byte) (err error) {
	return setsockopt(fd, level, opt, unsafe.Pointer(&value[0]), 4)
}

func SetsockoptIPMreq(fd, level, opt int, mreq *IPMreq) (err error) {
	return setsockopt(fd, level, opt, unsafe.Pointer(mreq), SizeofIPMreq)
}

func SetsockoptIPv6Mreq(fd, level, opt int, mreq *IPv6Mreq) (err error) {
	return setsockopt(fd, level, opt, unsafe.Pointer(mreq), SizeofIPv6Mreq)
}

func SetsockoptICMPv6Filter(fd, level, opt int, filter *ICMPv6Filter) error {
	return setsockopt(fd, level, opt, unsafe.Pointer(filter), SizeofICMPv6Filter)
}

func SetsockoptLinger(fd, level, opt int, l *Linger) (err error) {
	return setsockopt(fd, level, opt, unsafe.Pointer(l), SizeofLinger)
}

func SetsockoptString(fd, level, opt int, s string) (err error) {
	var p unsafe.Pointer
	if len(s) > 0 {
		p = unsafe.Pointer(&[]byte(s)[0])
	}
	return setsockopt(fd, level, opt, p, uintptr(len(s)))
}

func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (err error) {
	return setsockopt(fd, level, opt, unsafe.Pointer(tv), unsafe.Sizeof(*tv))
}

func Socket(domain, typ, proto int) (fd int, err error) {
	if domain == AF_INET6 && SocketDisableIPv6 {
		return -1, EAFNOSUPPORT
	}
	fd, err = socket(domain, typ, proto)
	return
}

func Socketpair(domain, typ, proto int) (fd [2]int, err error) {
	var fdx [2]int32
	err = socketpair(domain, typ, proto, &fdx)
	if err == nil {
		fd[0] = int(fdx[0])
		fd[1] = int(fdx[1])
	}
	return
}

func Sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) {
	if race.Enabled {
		race.ReleaseMerge(unsafe.Pointer(&ioSync))
	}
	return sendfile(outfd, infd, offset, count)
}

var ioSync int64